A typical data storage system includes a cabinet that holds a configuration of disk drive mechanisms. Each disk drive mechanism generally includes a disk drive capable of storing and retrieving computerized data, and some form of housing or frame for supporting that disk drive within a support structure of the cabinet.
One conventional disk drive mechanism (hereinafter referred to as the xe2x80x9cplastic housing disk drive mechanismxe2x80x9d) includes a plastic housing, a disk drive, and an interface card. The plastic housing surrounds and supports both the disk drive and the interface card. The plastic housing includes ventilation channels along its vertical sides to allow air to pass over portions of the disk drive in order to cool the disk drive. A support structure for the conventional plastic housing disk drive mechanism typically holds several of such disk drive mechanisms in a two dimensional array (i.e., multiple rows and columns).
FIG. 1 shows another conventional disk drive mechanism 20 (hereinafter referred to as the xe2x80x9cmetal frame disk drive mechanism 20xe2x80x9d). The metal frame disk drive mechanism 20 includes a chassis 22, disk drive 24, and a disk drive connector 26. The chassis 22 supports both the disk drive 24 and the disk drive connector 26. The chassis 22 includes a metal frame 28, a plastic actuator 30 and two compressible disk shaped members 32-1, 32-2 (collectively, disk shaped members 32). The metal frame 28 includes a main section 34, and a secondary section 36 which is riveted to the main section 34. Each section 34, 36 is made of thin galvanized metal, which is stamped and bent to generally conform to the shape of the disk drive 24. As such, when the disk drive 24 attaches to the chassis 22, the main section 34 extends along a side of the disk drive 24 in a parallel manner. The plastic actuator 30 fastens to a central area of the main section 34. The two disk shaped members 32 attach to corners of the secondary section 36 which are farthest from the main section 34, as shown in FIG. 1.
A support structure (not shown) for the conventional metal frame disk drive mechanism 20 holds a row of such mechanisms 20. Multiple support structures can be stacked on top of each other within a cabinet to form a two dimensional array of metal frame disk drive mechanisms 20 (i.e., multiple rows and columns).
When a user installs a conventional metal frame disk drive mechanism 20 into a support structure, the user slides edges 38 of the main section 34 into slots of the support structure, and then actuates the plastic actuator 30. In response, the disk drive connector 26 engages a corresponding connector of the support structure, and the disk shaped members 32 compress tightly against the support structure to firmly hold the metal frame disk drive mechanism 20 within the support structure.
Unfortunately, there are deficiencies with data storage systems using the above-described conventional disk drive mechanisms. In particular, these mechanisms are susceptible to vibration caused by mechanical component movement (e.g., disk drive head movement) during operation. It has been observed that such vibration can be up to 10 times greater along a vertical plane in which the magnetic platters and the disk drive head move, relative to other directions (e.g., horizontally, side-to-side, etc.). Random seek operations have been determined to provide particularly high vibration (e.g., rotational vibration in the plane of the platter and head movement). Such vibration can prevent the head from positioning itself properly relative to a magnetic platter of the disk drive. As a result, the platter must continue turning to enable the head to re-attempt to properly position itself (e.g., in order to read or write properly), thus lowering performance (e.g., access speeds).
Poor seek times due to disk drive vibration problems are, at least in part, a result of inadequacies in the supporting structure of the disk drive mechanism. For example, in connection with the conventional plastic housing disk drive mechanism, the plastic housing tends to stress and distort based on movement of the disk drive. Such movements (e.g., disk drive vibration due to head movement) are difficult to control using the plastic housing due to low modulus of elasticity in the plastic itself (e.g., uncontrolled energy absorption).
As another example, in connection with the metal frame disk drive mechanism 20, the metal section 34 in combination with the two disk shaped members 32 attempt to counteract the disk drive vibration. However, such vibration dampening is difficult to achieve due to the different approaches to supporting the disk drive mechanism 20 within the support structure used by the metal frame disk drive mechanism 20, i.e., a vertical metal section 34 on one side, and rubber disk shaped dampening members 32 on the other side.
Moreover, these conventional disk drive mechanisms have become more susceptible to vibration in recent years due to increases in disk drive rotation speeds (e.g., faster movement of internal mechanism components such as heads moving along magnetic platters spinning at faster rotations per minute or RPMs) and increases in disk drive densities (e.g., no longer using a dedicated platter for location tracking but instead using stripes/spokes to increase storage capacity). When used with conventional disk drive mounting mechanisms, such advances in disk drive technology have reduced the ability of disk drive heads to properly position themselves (i.e., read markings on the magnetic platters), and thus have made disk drives more susceptible to vibration problems.
In contrast to the above-described conventional disk drive mechanisms, the invention is directed to techniques for dampening vibration of a disk drive using a dampening member which is co-planar with a mid-plane of the disk drive, and which has at least a portion extending from a carrier toward a main assembly when the carrier is installed within the main assembly in order to dampen vibration of the disk drive when the disk drive is in operation. The use of the dampening member in this location results in vibration dampening which is superior to conventional disk drive mechanisms. Accordingly, disk drives configured in accordance with the invention provide high performance even in high rotation speed (i.e., high RPM) and high density configurations.
One arrangement of the invention is directed to a data storage system having a main assembly for holding multiple disk drive assemblies, and a disk drive assembly. The disk drive assembly includes a disk drive that stores and retrieves computerized data and a carrier coupled to the disk drive. The carrier supports the disk drive within the main assembly. The disk drive assembly further includes a dampening member coupled to the carrier at a location of the carrier which is co-planar with a mid-plane of the disk drive. At least a portion of the dampening member extends from the carrier toward the main assembly when the carrier is installed within the main assembly in order to dampen vibration of the disk drive when the disk drive is in operation. Since the dampening member is co-planar with the mid-plane of the disk drive, the dampening member dampens vibration along a critical direction providing substantial vibration isolation.
In one arrangement, the disk drive assembly further includes a lever that selectively (i) engages the disk drive assembly with the main assembly, and (ii) disengages the disk drive assembly from the main assembly. In this arrangement, the disk drive assembly further includes hardware which pivotably couples the lever to the carrier, and a dampening bushing which is positioned between the lever and the carrier by the hardware, in order to dampen vibration between the lever and the carrier. Here, the dampening bushing provides additional vibration isolation thus improving disk drive performance.
In one arrangement, the lever operates with the dampening member of the disk drive assembly to provide cantilevered support for the carrier of the disk drive assembly when the lever engages the disk drive assembly with the main assembly. Such support is superior to that of the conventional chassis disk drive mechanism which simply uses rubber disk shaped members in corners of one vertical side of a thin, galvanized metal frame. Accordingly, there is less vibration in the disk drive assembly of this arrangement.
In one arrangement, the main assembly includes connectors, and the disk drive assembly further includes a circuit board, coupled to the carrier, that mates with a connector of the main assembly. The circuit board provides friction between the carrier and the main assembly in order to dampen the vibration of the disk drive (e.g., in order to dampen vibration of a cantilevered end of the carrier) when the carrier is installed within the main assembly and when the disk drive is in operation. Accordingly, the circuit board improves the vibration isolation of the disk drive assembly.
In one arrangement, the main assembly includes support ribs, and the carrier of the disk drive assembly includes a set of guides that position a support rib of the main assembly along an area of an outer surface of the carrier. This area is co-planar with the mid-plane of the disk drive. The increase in contact area between the carrier and the main assembly, which is focused along the mid-plane of the disk drive, provides improved vibration dampening. Accordingly, the disk drive performance is improved and the design is less susceptible to increases in disk drive speed and density.
In one arrangement, the carrier of the disk drive assembly is formed by stamping, bending and welding a metal sheet into a single, contiguous metallic frame. This arrangement provides stiffness which is superior to that of the metal frame of the conventional metal frame disk drive mechanism, and that of the plastic housing of the plastic housing disk drive mechanism. Accordingly, this arrangement provides superior control over disk drive movement and energy absorption for improved vibration dampening.
The features of the invention, as described above, may be employed in data storage systems, devices and other computer-related components such as those manufactured by EMC Corporation of Hopkinton, Mass.